The present invention relates to apparatus and methods for removably attaching temporary traction augmenting devices to a vehicle tire or the like. More particularly, the present invention relates to apparatus and methods for temporarily enhancing the traction qualities of a vehicle tire by providing an assembly which can be removably attached to the tire so as to increase its traction relative to a surface whose friction characteristics have been reduced for various reasons. The present invention is especially useful for increasing the traction of a vehicle tire in mud, snow or even on icy surfaces.
It has been long recognized that the configurations of automobile tire treads which are suitable for use on relatively dry surfaces are not suitable when employed in relatively low friction environments such as when operated over snow, mud or ice. The most popular response to the traction augmenting problem has been through the various configurations of generally loose chains which are attached and tightened around the tire rim. Such chains are awkward to attach to the vehicle because of their pliant nature which also makes them difficult to maintain in a relatively tight-fitting configuration around the tire. Still further, such chains are frequently required for only short periods and are thereafter driven over clear road surfaces. Under such conditions, the chains tend to break after relatively short periods thus rendering them unsuitable for further use.
It has also been suggested that rigid lugs be attached around the tire circumference to provide the traction augmenting results. Examples of such rigid lugs are shown in U.S. Pat. Nos. 1,283,729 by Ginley, 1,867,773 by Spidla et al, 2,696,237 by Doughty, 2,423,759 by Edwards and 2,936,016 by Stack. The rigid lugs of such devices are interconnected by chains, serially coupled linkages, take-up cables with releasable ratchet arrangements and the like. However, because of the relatively inflexible nature of such rigid lugs and the necessary positioning of the interconnecting linkages, such devices tend to produce undesirable wear or even damage to the vehicle tire under conditions of under-inflation or even from normal tire flexure during usage.
Tire manufacturers have approached the traction augmenting problem by tailoring special tread configurations such as in the so-called snow tire arrangement and further have embedded studs or other traction augmenting elements within the tire to assist it in frictionally engaging icy surfaces. Although a sometimes acceptable compromise between tire chains or rigid lugs and standard tire tread traction, such snow or stud tires are relatively expensive, frequently tend to wear rapidly and suffer other disadvantages such as noise and road surface destruction.
Accordingly, efforts have been directed towards providing a detachable temporary traction augmenting arrangement for tires which can somewhat simulate the presence of snow or stud tires. For instance, U.S. Pat. No. 3,506,051 by Mathews shows an arrangement for effectively covering an existing tire with tire casement sections having snow treads and reinforcing bars. Another arrangement for providing somewhat flexible temporary crossbars which can include studs embedded therein is shown in U.S. Pat. No. 2,540,230 by Andrews. Both devices require relatively complex attaching arrangements and further require acceptance of the hazard of sidewall damages from the positioning of the relatively rigid attaching apparatus.